Star light, star bright, pulsars were found on a radar site

Courtesy of NASA This is a diagram of the environment around the pulsar at the heart of the Crab nebula, based on images taken by the Hubble Space Telescope. The jets of high speed particles, and the outward moving "equatorial wisps," are powered by the pulsar, which is the rapidly rotating crushed remnant of an exploded star.

Courtesy of NASA/CXC/SAO The explosion was seen on Earth in 1054 AD. At the center of the nebula is a rapidly spinning neutron star, or pulsar that emits pulses of radiation 30 times a second. The image shows the central pulsar surrounded by tilted rings of high-energy particles that appear to have been flung outward over a distance of more than a light year from the pulsar. Perpendicular to the rings, jet-like structures produced by high-energy particles blast away from the pulsar. The diameter of the inner ring in the image is about one light year, more than 1000 times the diameter of our solar system. The X rays from the Crab nebula are produced by high-energy particles spiraling around magnetic field lines in the Nebula. The bell-shaped appearance of the Nebula could be due to the way this huge magnetized bubble was produced or to its interaction with clouds of gas and dust in the vicinity. -NASA/CXC/SAO

Courtesy of NASA Poised over where Manhattan is, a pulsar is a neutron star, the crushed core of a star that has exploded. Neutron stars crush half a million times more mass than Earth into a sphere no larger than Manhattan. Some of these objects spin at 43,000 revolutions per minute.

Sun City resident Charles Schisler may have been the first person to discover and record pulsars but no one knew until 40 years later.

The retired U.S. Air Force member recently shared his experience and knowledge with the Astronomy Special Interest Group of the community’s computer club.

In 1967, Schisler was assigned to Clear Air Force Station, Alaska, to man the highly sensitive radars. During a four-hour shift two months into his tour of duty, an unusual radar signal attracted his attention.

“Our radars could see 2,800 miles out into space,” Schisler said while sitting in his Sun City home. He described the faint signal he saw as a minor strobe. It had no meaning as far as his assignment was concerned but it was unusual. He made a note of it and looked for it the next day. It appeared four minutes earlier and repeated the pulsing signal it had made the day before.

Forty years later at McGill University, Montreal, Schisler was able to reveal his research to 185 professional astronomers and received a standing ovation.

“When they saw this amateur stumbled upon something, was curious enough and found out about this stuff, they were impressed,” Schisler said.

“A pulsar is a neutron star that emits beams of radiation that sweep through Earth’s line of sight. Like a black hole, it is an endpoint to stellar evolution,” according to the NASA Goddard Space Flight Center website. In other words, it’s what is left when a star dies.

“I knew that stars appeared four minutes earlier every night as the earth rotated so the next day I was ready,” he said. Sure enough, on the third day it appeared again — four minutes earlier. Now Schisler was more than curious. He wanted to find out where in space this signal originated. Having no more interest in nature than the average person, Schisler said, he did not know astronomy but as a navigator/bombardier he was trained in celestial navigation.

“I drove my little Renault up to the University of Alaska in Eielson to find celestial navigational tables for the local area,” Schisler said. He was sent to find Ken Phillip in the Arctic biology department, who also happened to be knowledgeable in astronomy.

Philip and Schisler discussed the discovery, located the coordinates on the celestial charts and found the spot to be in the center of the Crab Nebula, a supernova. This supernova in the constellation of Taurus was recorded in 1054 by Chinese, Arab and Japanese astronomers and is about 6,300 light years away. For reference, one light year equals about 5,878,786,100,000 miles. The pulsar Schisler found was about 18 miles wide.

23 minutes of fame

Having satisfied his curiosity, he returned to the base and continued to document the pulsar and discovered 12 others. He was not alone in his observations. In May of 1968, a month before he retired and left Alaska, Schisler heard on a shortwave radio that a Cambridge, England, group had discovered a pulsing signal from the same location in the Crab Nebula.

Because of the sensitive nature of his assignment and the equipment he was using, Schisler was unable to do anything with his research until 40 years later, after the base had been closed down.

“In looking back now, I should have realized that if he knew what I knew and I knew what he knew, we could have made possibly made the announcement ourselves,” he said.

He has not gone unrecognized for his efforts. A friend, Hana Hudecek, happened to talk about a visit to the Pisgah Astronomy Research Institute in North Carolina. Schisler sent its director an email about his time in Alaska. That was forwarded to Richard Manchester, an authority on astronomic pulsars in Australia.

After examining the documentation, Manchester invited Schisler and his wife to be his guests at the Montreal conference celebrating “40 Years of Pulsars” and give a presentation on the discovery.

“I had no idea what they were talking about most of the time. I found it very interesting,” Schisler said, “but I got a standing ovation from all of these people, including Jocelyn Bell-Burnell who was the discoverer on the Cambridge team. I’ve never been a great one for trying to be famous but I got my 23 minutes of fame.”

At the podium

Ralph Horvath, chairman of the Skywatchers astronomy Special Interest Group, said Schisler was invited to give a talk to the members after hearing about his experience.

“He attended one of our meetings and he’s not really an astronomer. He’s more of a mathematician and he relayed to us that he discovered pulsars about a year before anybody else,” said Horvath, “He did a lot of research and by mathematics he worked backwards to find out what star was pulsing and no one had ever done that before.

“The interesting fact that he told me was being a radar guy, they were looking for missiles coming over Alaska and the United States from Russia. Radar is the only one that recognized the pulses.”

Horvath said Skywatchers member Jerry Jeffries gave an in-depth presentation of how pulsars are developed, what they do and how to recognize them.

“I’m always amazed at our residents, they always have wonderful achievements and the trouble is we don’t recognize it as such,” Horvath said. “It’s wonderful that he was recognized even though it was 40 years later.”